Synthesis, biological evaluation and 3D-QSAR studies of novel 5-phenyl-1H-pyrazol cinnamamide derivatives as novel antitubulin agents

A new polyazomethine-based pyrazole moiety and its reinforced nanocomposites @ ZnO for antimicrobial applications

A new class of biologically active polyazomethine/pyrazole and their related nanocomposites, polyazomethine/pyrazole/zinc oxide nanoparticles, have been successfully synthesized through the polycondensation technique in the form of polyazomethine pyrazole (PAZm/Py4-6) and polyazomethine/pyrazole/zinc oxide nanoparticles (PAZm/Py/ZnOa-c). The polymeric nanocomposites were prepared with a 5% loading of zinc oxide nanofiller using the same preparation technique, in addition to the help of ultrasonic radiation. The characteristics of the new polymers, such as solubility, viscometry, and molecular weight, were examined. All the polymers were completely soluble in the following solvents: concentrated sulfuric acid, formic acid, dimethylformamide, dimethyl sulfoxide, and tetrahydrofuran. Furthermore, the weight loss of the polyazomethine pyrazole (4, 5, and 6) at 800 °C was 67%, 95%, and 86%, respectively, which indicates the thermal stability of these polymers. At 800 °C, the polyazomethine/pyrazole/zinc oxide nanoparticles (a, b, and c) lost 74%, 68%, and 75% of their weight, respectively. This shows that adding zinc oxide nanoparticles made these compounds more stable at high temperatures. The X-Ray diffraction pattern of the polyazomethine pyrazole (PAZm/Py4-6) shows a number of sharp peaks with varying intensities. The polymers that were studied had straight crystal structures. Furthermore, the measurements of polyazomethine/pyrazole/zinc oxide nanoparticles (PAZm/Py/ZnOa-c) indicate a good merging of zinc oxide nanoparticles into the matrix of polymers. The antimicrobial activity of polymers and polymer nanocomposites was tested against some selected bacteria and fungi. The synthesized polymer (c) shows the highest activity against the two types of gram-negative bacteria selected. Most tested compounds were found to be effective against gram-positive bacteria except polyazomethine pyrazole (PAZm/Py5) and polyazomethine pyrazole (PAZm/Py6), which do not exhibit any activity. The synthesized polymers and their related nanocomposites were tested for their ability to kill the chosen fungi. All of them were effective against Aspergillus flavus, but only polyazomethine pyrazole (PAZm/Py4) and polyazomethine/pyrazole/zinc oxide (PAZm/Py/ZnOc) were effective against Candida albicans.

Design, synthesis and biological evaluation of N-benzylaryl cinnamide derivatives as tubulin polymerization inhibitors capable of promoting YAP degradation with potent anti-gastric cancer activities

In this work, we utilized the N-benzylaryl derivative 9 as a lead compound and employed the molecular hybridization strategy by introducing cinnamoyl fragments to successfully design and synthesize 33 novel N-benzylaryl cinnamide derivatives 15a∼15 ag. The in vitro antiproliferative activities were explored, and the preliminary analysis and summary of their structure-activity relationship were conducted. The majority of the compounds demonstrated significant inhibitory potency on MGC-803, HCT-116 and KYSE450 cells with IC50 values below 0.5 μM. Among them, compound 15e (MY-1076) exhibited the most effective effect on the proliferative inhibition of MGC-803, SGC-7901, HCT-116 and KYSE450 cells with IC50 values of 0.019, 0.017, 0.020 and 0.044 μM, respectively, which is more potent than colchicine and the lead compound 9. Additionally, compound 15e (MY-1076) still exhibited significant inhibitory proliferation activity against 13 other types of tumor cells (IC50 values < 0.1 μM). Further studies revealed that compound 15e (MY-1076) could effectively inhibit tubulin polymerization by acting on the β-tubulin colchicine binding site, thereby disrupting microtubule network assembly and mitotic progression. Additionally, compound 15e (MY-1076) also demonstrated a notable inhibitory effect on the oncogenic protein YAP by inducing its degradation. Compound 15e (MY-1076) could dose-dependently induce G2/M phase arrest and cell apoptosis, effectively inhibit the colony formatting ability and cause morphological changes in MGC-803 and SGC-7901 cells. Compound 15e (MY-1076) exhibited significant regulatory effects on the expression levels of cell cycle and apoptosis-related proteins. Taken together, we here reported a novel N-benzylaryl cinnamide derivative 15e (MY-1076) as a tubulin polymerization inhibitor capable of promoting degradation of YAP, which held great potential as an anti-gastric cancer agent.

Design, synthesis, in vitro and in silico evaluation of anti-colorectal cancer activity of curcumin analogues containing 1,3-diphenyl-1H-pyrazole targeting EGFR tyrosine kinase

Recent studies have shown that monocarbonyl analogues of curcumin (MACs) and 1H-pyrazole heterocycle both demonstrated promising anticancer activities, in which several compounds containing these scaffolds could target EGFR. In this research, 24 curcumin analogues containing 1H-pyrazole (a1-f4) were synthesized and characterized by using modern spectroscopic techniques. Firstly, synthetic MACs were screened for cytotoxicity against human cancer cell lines such as SW480, MDA-MB-231 and A549, from which the 10 most potential cytotoxic compounds were identified and selected. Subsequently, the selected MACs were further screened for their inhibition against tyrosine kinases, which showed that a4 demonstrated the most significant inhibitory effects on EGFR^WT and EGFR^L858R. Based on the results, a4 further demonstrated its ability to cause morphological changes, to increase the percentage of apoptotic cells, and to increase caspase-3 activity, suggesting its apoptosis-inducing activity on SW480 cells. In addition, the effect of a4 on the SW480 cell cycle revealed its ability to arrest SW480 cells at G₂/M phase. In subsequent computer-based assessments, a4 was predicted to possess several promising physicochemical, pharmacokinetic, and toxicological properties. Via molecular docking and molecular dynamics simulation, a reversible binding mode between a4 and EGFR^WT, EGFR^L858R, or EGFR^G719S, remained stable within the 100-ns simulation due to effective interactions especially the hydrogen bonding with M793. Finally, free binding energy calculations suggested that a4 could inhibit the activity of EGFR^G719S more effectively than other EGFR forms. In conclusion, our work would provide the basis for the future design of promising synthetic compounds as anticancer agents targeting EGFR tyrosine kinase.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of 1-Aryl-1H-pyrazole-Fused Curcumin Analogues as Anticancer Agents

Addressing the growing burden of cancer and the shortcomings of chemotherapy in cancer treatment are the current research goals. Research to overcome the limitations of curcumin and to improve its anticancer activity via its heterocycle-fused monocarbonyl analogues (MACs) has immense potential. In this study, 32 asymmetric MACs fused with 1-aryl-1H-pyrazole (7a-10h) were synthesized and characterized to develop new curcumin analogues. Subsequently, via initial screening for cytotoxic activity, nine compounds exhibited potential growth inhibition against MDA-MB-231 (IC₅₀ 2.43-7.84 μM) and HepG2 (IC₅₀ 4.98-14.65 μM), in which seven compounds showing higher selectivities on two cancer cell lines than the noncancerous LLC-PK1 were selected for cell-free in vitro screening for effects on microtubule assembly activity. Among those, compounds 7d, 7h, and 10c showed effective inhibitions of microtubule assembly at 20.0 μM (40.76-52.03%), indicating that they could act as microtubule-destabilizing agents. From the screening results, three most potential compounds, 7d, 7h, and 10c, were selected for further evaluation of cellular effects on breast cancer MDA-MB-231 cells. The apoptosis-inducing study indicated that these three compounds could cause morphological changes at 1.0 μM and could enhance caspase-3 activity (1.33-1.57 times) at 10.0 μM in MDA-MB-231 cells, confirming their apoptosis-inducing activities. Additionally, in cell cycle analysis, compounds 7d and 7h at 2.5 μM and 10c at 5.0 μM also arrested MDA-MB-231 cells in the G₂/M phase. Finally, the results from in silico studies revealed that the predicted absorption, distribution, metabolism, excretion, and the toxicity (ADMET) profile of the most potent MACs might have several advantages in addition to potential disadvantages, and compound 7h could bind into (ΔG -10.08 kcal·mol^-1) and access wider space at the colchicine-binding site (CBS) than that of colchicine or nocodazole via molecular docking studies. In conclusion, our study serves as a basis for the design of promising synthetic compounds as anticancer agents in the future.

A novel tubulin inhibitor, 6h, suppresses tumor-associated angiogenesis and shows potent antitumor activity against non-small cell lung cancers

Tumor angiogenesis is closely associated with the metastasis and progression of non-small cell lung cancer (NSCLC), a highly vascularized solid tumor. However, novel therapeutics are lacking for the treatment of this cancer. Here, we developed a series of 2-aryl-4-(3,4,5-trimethoxy-benzoyl)-5-substituted-1,2,3-triazol analogs (6a-6x) as tubulin colchicine-binding site inhibitors, aiming to find a novel promising drug candidate for NSCLC treatment. We first identified 2-(2-fluorophenyl)-3-(3,4,5-trimethoxybenzoyl)-5-(3-hydroxyazetidin-1-yl)-2H-1,2,3-triazole (6h) as a hit compound, which inhibited angiogenesis induced by NSCLC cells both in vivo and in vitro. In addition, our data showed that 6h could tightly bind to the colchicine-binding site of tubulin and inhibit tubulin polymerization. We also found that 6h could effectively induce G2/M cell cycle arrest of A549 and H460 cells, inhibit cell proliferation, and induce apoptosis. Furthermore, we showed 6h had the potential to inhibit the migration and invasion of NSCLC cells, two basic characteristics of tumor metastasis. Finally, we found 6h could effectively inhibit tumor progression in A549 xenograft mouse models with minimal toxicity. Taken together, these findings provide strong evidence for the development of 6h as a promising microtubule colchicine-binding site inhibitor for NSCLC treatment.

Tetrabutylammonium Iodide Mediated Sulfenylation of Poly­substituted 1H-Pyrazol-5-amines with Arylsulfonyl Hydrazides

A TBAI-mediated sulfenylation of N,3-diaryl-1-arylsulfonyl-1H-pyrazol-5-amines with arylsulfonyl hydrazides has been established, and an expanded inventory of N,5-diaryl-4-(arylthio)-1H-pyrazol-3-amines was constructed through C–S bond formation and N–S bond breaking. Mechanistic investigations suggest thiosulfonate as a key intermediate in the sulfenylation, and the detosylation is promoted by the generated arylsulfinic acid. The method is characterized by simple operating conditions, broad substrate range as well as gram-scale reaction.

Design, synthesis and bioevaluation of 2,7-diaryl-pyrazolo[1,5-a]pyrimidines as tubulin polymerization inhibitors

Two series of 2,7-diaryl-pyrazolo[1,5-a]pyrimidines as tubulin polymerization inhibitors were designed to restrict bioactive configuration of (E,Z)-vinylogous CA-4. All of the target compounds were synthesized and then evaluated for their in vitro antiproliferative activities against three cancer cell lines (MCF-7, SGC-7901 and A549). Among them, 6d exhibited the most potent antiproliferative activity against the MCF-7 with IC₅₀ value of 0.047 μM. Moreover, 6d significantly inhibited tubulin polymerization, disrupted microtubule networks, arrested cell cycle at G2/M phase, induced apoptosis and hindered cancer cell migration. Colchicine competition assay and molecular docking studies suggested that 6d could interact with tubulin by binding to the colchicine site.

NIS-promoted three-component reaction of 3-oxo-3-arylpropanenitriles with arylsulfonyl hydrazides

A new three-component reaction of 3-oxo-3-arylpropanenitriles with arylsulfonyl hydrazides has been established, and an expanded inventory of 3-aryl-4-(arylthio)-1H-pyrazol-5-amines is synthesized by sequential cyclization and sulfenylation reactions under the action of NIS. In addition to the attractive features of multicomponent reactions, the protocol presents broad substrate scope, good functional group tolerance and mild reaction conditions. The utility of this procedure is further established by gram-scale synthesis as well as the diversified transformations of the products to useful compounds.

Recent Progress on Anticancer Agents Incorporating Pyrazole Scaffold

The search of new anticancer agents is considered as a dynamic field of medicinal chemistry. In recent years, the synthesis of compounds with anticancer potential has increased and a large number of structurally varied compounds displaying potent anticancer activities have been published. Pyrazole is an important biologically active scaffold that possessed nearly all types of biological activities. The aim of this review is to collate literature work reported by researchers to provide an overview on in vivo and in vitro anticancer activities of pyrazole based derivatives among the diverse biological activities displayed by them and also presents recent efforts made on this heterocyclic moiety regarding anticancer activities. This review has been driven from the increasing number of publications, on this issue, which have been reported in the literature since the ending of the 20th century (from 1995-to date).

Synthesis and structure-activity relationships of pyrazolo-[3,4-b]pyridine derivatives as adenosine 5'-monophosphate-activated protein kinase activators

A series of pyrazolo[3,4-b]pyridine derivatives were designed, synthesized, and evaluated for their activation activity toward adenosine 5'-monophosphate-activated protein kinase (AMPK). According to the enzyme activity, the pyrazole N-H exposure and para substitution on the diphenyl group were proved to be essential for the activation potency. Compound 17f showed equal activation compared with A-769662. In the molecular modeling study, compound 17f exhibited important hydrogen bond interaction with Lys29, Asp88, and Arg83. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays on the NRK-49F cell line showed that potent enzyme activators could effectively inhibit cell proliferation, especially for 17f (EC₅₀ [AMPKα1γ1β1] = 0.42 μM, efficacy = 79%; IC₅₀ [NRK-49F cell line] = 0.78 μM). These results might provide new insights to explore novel AMPK activators.

Identification of Essential 2D and 3D Chemical Features for Discovery of the Novel Tubulin Polymerization Inhibitors

Background:

Tubulin polymerization inhibitors interfere with microtubule assembly and their functions lead to mitotic arrest, therefore they are attractive target for design and development of novel anticancer compounds.

Objective:

The proposed novel and effective structures following the use of three-dimensionalquantitative structure activity relationship (3D-QSAR) pharmacophore based virtual screening clearly demonstrate the high efficiency of this method in modern drug discovery.

Method:

Combined computational approach was applied to extract the essential 2D and 3D features requirements for higher activity as well as identify new anti-tubulin agents.

Results:

The best quantitative pharmacophore model, Hypo1, exhibited good correlation of 0.943 (RMSD=1.019) and excellent predictive power in the training set compounds. Generated model AHHHR, was well mapped to colchicine site and three-dimensional spatial arrangement of their features were in good agreement with the vital interactions in the active site. Total prediction accuracy (0.92 for training set and 0.86 for test set), enrichment factor (4.2 for training set and 4.5 for test set) and the area under the ROC curve (0.86 for training set and 0.94 for the test set), the developed model using Extended Class FingerPrints of maximum diameter 4 (ECFP_4) was chosen as the best model.

Conclusion:

Developed computational platform provided a better understanding of requirement features for colchicine site inhibitors and we believe the results of this study might be useful for the rational design and optimization of new inhibitors.

Design, synthesis, and biological evaluation of 2,3-diphenyl-cycloalkyl pyrazole derivatives as potential tubulin polymerization inhibitors

Several novel cycloalkyl-fused 2,3-diaryl pyrazole derivatives were designed, synthesized, and evaluated as potential anti-tubulin agents. Compound A10 exhibited the most potent antiproliferative activity against a panel of cancer lines (IC₅₀  = 0.78-2.42 μM) and low cytotoxicity against 293T & L02 (CC₅₀ values of 131.74 and 174.89 μM, respectively). Moreover, A10 displayed inhibition of tubulin polymerization in vitro, arrested the G2/M phase of the cell cycle, changed morphology of tubulin, increased intracellular reactive oxygen species, and induced apoptosis of HeLa cells. Docking simulation and 3D-QSAR models were performed to elaborate on the anti-tubulin mechanism of the derivatives. The inhibition of monoclonal colony formation provided more intuitional data to verify the possibility of A10 as a novel tubulin assembling inhibitor.

Evolution of 1, 3, 5-trisubstituted bipyrazole scaffold based platinum(II) complexes as a biological active agent

Square planar mononuclear platinum(II) complexes having general formula [Pt(Lⁿ)Cl₂], (where, Lⁿ = L^1-4) were synthesized with neutral bidentate heterocyclic 1,3,5-trisubstituted bipyrazole based ligands. The synthesized compounds were characterized by physicochemical method such as TGA, molar conductance, micro-elemental analysis and magnetic moment, and spectroscopic method such as, FT-IR, UV-vis, ¹H NMR, ¹³C NMR and mass spectrometry. Biological applications of the compounds were carried out using in vitro brine shrimp lethality bioassay, in vitro antimicrobial study against five different pathogens, and cellular level cytotoxicity against Schizosaccharomyces pombe (S. Pombe) cells. Pt(II) complexes were tested for DNA interaction activities using electronic absorption titration, viscosity measurements study, fluorescence quenching technique and molecular docking assay. Binding constants (K_b) of ligands and complexes were observed in the range of 0.23-1.07 × 10⁵ M^-1 and 0.51-3.13 × 10⁵ M^-1, respectively. Pt(II) complexes (I-IV) display an excellent binding tendency to biomolecule (DNA) and possess comparatively high binding constant (K_b) values than the ligands. The DNA binding study indicate partial intercalative mode of binding in complex-DNA. The gel electrophoresis activity was carried out to examine DNA nuclease property of pUC19 plasmid DNA.

Synthesis and antiproliferative activity of 2-aryl-4-(3,4,5-trimethoxybenzoyl)-1,2,3-triazol derivatives as microtubule-destabilizing agents

A series of 2-aryl-4-(3,4,5-trimethoxybenzoyl)-1,2,3-triazols were designed as analogs of substituted methoxybenzoyl-aryl-thiazole (SMART) under the consideration of geometric features.

Design and synthesis of pyrazole/isoxazole linked arylcinnamides as tubulin polymerization inhibitors and potential antiproliferative agents

A series of pyrazole/isoxazole linked arylcinnamide conjugates were synthesized and investigated for their cytotoxic activity against a panel of four human cancer cell lines. Most of them have shown significant cytotoxicity apart from potential tubulin depolymerization activity.